Gov. Dannel P. Malloy will propose $100 million for downtown Hartford’s XL Center in the state’s capital improvement budget — a move that is sure to reignite the debate over whether it’s worth sinking more state money into the aging arena.

Malloy revealed the plan Monday in a briefing on proposed changes to the state budget that begins June 1, the second half of the state’s current two-year fiscal plan.

The proposal, which would need the approval of the legislature and would be financed by selling state bonds, comes as the Capital Region Development Authority prepares to seek a buyer this spring for the 42-year old arena to test the viability of the option.

Last year, state lawmakers approved $40 million for renovations but they also mandated that a buyer be sought by June, 2019.

In 2014, the legislature approved $35 million on renovations that spruced up a drab interior, added new seating and a bar facing the arena. Those improvements were supposed to extend the life of arena until a long-term plan was developed.

But ultimately, there was not legislative support for a $250 million, top-to-bottom makeover recommended by a consultant hired by the authority, which oversees the arena’s operation.

“I think the hope was on the legislative side that somebody would come along, buy it and put $250 million into it and run it for the good of the city of Hartford and the state of Connecticut,” Malloy said at Monday’s briefing. “No one has said that yet.”

The $40 million approved last year was aimed at making the arena more attractive to a potential buyer, partly by purchasing the atrium and storefronts along Trumbull Street. Those spaces also could be sources of revenue for a new owner.

Michael W. Freimuth, the authority’s executive director, said Monday the $100 million or some part of it could be used as a “public contribution” to attract a private buyer. Or if there isn’t interest in a purchase, the $100 million could be used for renovations, Freimuth said.

One indication that it may be tough to find a buyer came last year. The authority sought proposals for a public-private partnership and drew just one bid.

On Monday, Malloy reiterated his longtime support for the arena. He said he sees the arena as a crucial cog in downtown Hartford’s revitalization, an amenity that benefits restaurants and bars and is a draw for young professionals considering living downtown.

Sen. Joseph Markley, R-Southington, has been a frequent critic of funding renovations at the XL, especially as the state has wrestled with budget deficits.

On Monday, Markley renewed the criticism saying that it appeared the $100 million was part of a broader strategy to keep seeking money for renovations until the $250 million — or more — was spent.

Markley said he understands the downsides of having an empty arena in the middle of downtown. But if a buyer can’t be found either with or without the state kicking in money, then Hartford may be forced to take a hard look at the arena as did New Haven.

New Haven closed its Coliseum and knocked it down.

“If someone isn’t willing to take over out right or with state participation, we have to make the decision of whether to continue with it or not,” Markley said.